Answer to Question #185940 in Databases | SQL | Oracle | MS Access for mansoor

Question

Consider relation EMPLOYEE. Suppose there are two applications that access EMPLOYEE. The

first is issued at four sites and attempts to find the Salary of employee by given their numbers.

Assume that we have set the simple predicates for application 1 are P1: Job-Title=

PRESIDENT,P2: Job-Title= MANAGER, P3: Job-Title= ANALYST The second application is

issued at two sites where the employee with a salary less than 15,00 USD are managed at one site,

whereas those with salary grater then 15, 00 USD are managed at a second site. Suppose we set

the simple predicates for site 2 are P4: Salary<15,00 USD, P5: Salary>=15,00 USD and P6:

Commission= 400.00 USD.

1. Perform a horizontal fragmentation of relation EMP with respect to the predicates above.

2. Explain why the resulting fragments of Employee does not fulfill the correctness rules of

fragmentation.

Answer 1

select e.Emp_ld
from employeemanagementsystem.employees as e
where e.salary>1500;

select e.Emp_ld
from employeemanagementsystem.employees as e
where e.salary<1500;